Automatic tail gate lock



July 30, 1935. T. M. E. YEAGER 2,009,466

AUTOMATIC TAIL GATE LOCK Filed July 11, 1934 2 Sheets-Sheet l 1:115- .NVENTQR;

. 112012205111? )ayer,

@7 5% wily 6M H11 ATTORNEYS July 30, 1935. T. M. E. YEAGER AUTOMATIC TAIL GATE. LOCK Filed'July 11, 1934 2 Sheets-Sheet 2 w MW E 6 6M WI y a m mv B H rtj' MW, 112? Patented July 30, 1935 AUTOMATIC TAIL GATE oc Thomas M. E. Yeager, Allentown, Pa, assignor to International Motor Company, New N. Y., a corporation of Delaware York,

Application July 11, 1934, Serial l\lo..734,627ir' 1 Claim.

This invention relates to a simple lock for the tail gate on dump bodies which shall be operable automatically to hold the gate closed when the body is in normal position while releasing the gate for opening when the body is tilted for dumping. The principal object of the present invention is to provide such mechanism which shall be simple in construction, positive and invariable in action and rugged for the type of work for which designed. A further object of the invention is to provide automatic mechanism of the character described which can be locked positively out of action so as to secure the gate against movement even when the body is tilted and afford, if desired, a pivotal support about which the gate can be rocked. Such provision is especially desirable where tail gates are of the double hinged type movable generally either about the lower edge or about the upper edge, as may be required.

In accordance with the principal object of the invention the tail gate latch is held locked by the weight of the dump body when in normal position and is of such a character that when the body is tilted the latch is free to release under the pressure exerted by the tail gate itself. By this relationship of parts springs and other devices for the same purpose are eliminated and gravity is employed both for the purpose of moving the latch and for holding the latch in locked position.

The device will be described more fully in connection with the accompanying drawings, in which:

Figure 1 is a View in side elevation of a fragment of a dump vehicle showing the relationship of the parts comprising the improved mechanism, the same parts being shown in their relationship when the body is tilted, as indicated in dotted lines.

Figure 2 is a fragmentary view on a larger scale taken on the plane indicated by the line 22 of Figure 1 and looking in the direction of the arrows and showing the restraining elements for the latch.

Figure 3 is fragmentary view in side elevation showing the parts illustrated in Figures 1 and 2 when the body is in normal position.

The dump body a. may be of any type adapted to be tilted for discharging the contents. Its rear end is closed by a tail gate 17 which may be hingedly supported at its upper edge by pins one of which is shown at c and its lower edge by pins one of which is shown at d. The gate is locked for pivotal movement about the pin d by means of a latch e. The latch is pivoted at 6. When the latch e is released as indicated by dotted lines in Figure l and the body tilted, the tail gate 27 is free to swing open about the pin under the influence of gravity. The improved mechanism has to do with the automatic locking and release of the latch e when the body a is in normal position and when it is tilted, respectively. The latch c has pivoted thereto at a link I which in turn is pivoted to a supporting pivotal link 9 carried with the frame of the body. To the same link 9 is pivotally attached a rod f extending forwardly for substantially the length of the body. At its forward end the rod f is pivoted to one arm of a bell crank lever, the other arm I of which may conveniently extend rearwardly. The bell crank lever is pivotally supported on a pin it carried by a bracket 1 secured to the forward edge of the frame of the dump body a. On the chassis 7c of the vehicle is supported a plate Z on which the flattened arm of the bell crank rests when the body is in normal position. The linkage described is so related that When the body a rests in its normal position with the arm I of the bell crank engaging the plate I on the chassis, the latch e is held in looking engagement with the pin d on the tail gate so as to hold it closed. At this time, the action of gravity impressed on the dump body through the intermediary of the bell crank constitutes the locking median for the latch a. When the forward end of the body is raised so that the arm f of the bell crank is carried out of contact with the plate I the latch e is free to rock about its pivotal support e. The action of gravity on the tail gate b taken with the pressure exerted by the contents of the body on the tail gate effectively serve to move the latch and thus release the pin (1 from restraint and thereby permit the contents of the body to be discharged. The relationship of the parts during dumping is illustrated clearly by dotted lines in Figure 1. Contrariwise, when the forward end of the body is lowered gravity will bring the tail gate 1) back into normal position and the arm I of the bell crank will again engage the plate Z. Such engagement results in the rocking of the bell crank about its pivotal support it thereby moving the rod f forwardly and locking the latch e on the pin d.

Under some circumstances it may be desired to swing the tail gate b about the pin 11 after releasing the top pin 0. To accomplish this it is necessary that the improved locking mechanism shall be secured against automatic release of the latch 6. One simple way of accomplishing this condition is to insert a pin m through aligned openings 1" in the supporting bracket i for the bell crank. In this position the pin 2" positively prevents rocking of the arm I of the bell crank about its pivot and release of the latch 6 when the forward end of the body is raised. When not in use the pin m may be carried in a supporting bracket 11. on the frame of the body, a cotter pin 0 or the like holding it against dislodgment.

Changes in matters of design of the various elements may be made without departing from the invention.

I claim as my invention:

In combination with a chassis and a tilting body, a tail gate releasably pivoted adjacent its upper edge, a latch engaging the lower edge operatively, a bifurcated bracket secured to the forward end of the body, a bell crank lever pivoted between the bifurcations of the bracket, a link pivoted adjacent the rear of the body and beneath the plane of the latch, linkage interposed operatively between one arm of the said bell crank lever and the link, linkage connected between the last named link and the latch and normally lying in a plane perpendicular to the plane of the latch, a plate on the chassis engaged by the other arm of the bell crank lever when the body is lowered onto the chassis whereby the bell crank lever is rocked to move the latch into locking engagement with the tail gate, and a pin adapted to be inserted through the bifurcations of the bracket to hold the bell crank against rocking when the body is tilted, whereby the tail gate may be swung about the latch as a pivot when the pivot at its upper edge is released.

THOMAS M. E. YEAGER. 

